Currently, refrigerants such as refrigerant 12, 22, 500 and 502 are extensively used in air conditioners and heat exchangers in cars, trucks, homes, commercial buildings and wherever a refrigeration unit operates. The political atmosphere in the United States and world wide is limiting the production of these refrigerants. It is believed by some that the release of halogens, such as contained in refrigerants 12, 22, 500 and 502, are harmful and have a deleterious effect on the ozone layer which surrounds and protects the earth from ultraviolet solar radiation.
As such, the supply of refrigerant is limited and the demand high. Therefore, there is an increasing demand for a unit or device that will recover refrigerant, from an air conditioner, heat exchanger or the like, filter, clean and recycle the refrigerant. Typically, without such a unit or device an air conditioner or heat exchanger undergoing a repair is vented to the atmosphere. Thereby, wasting the refrigerant, and resulting in extra costs to replace the refrigerant and potentially contributing to the harmful effects of halogens in the ozone layer.
In the prior art there are several types of systems available in this area. U.S. Pat. No. 4,261,178 discloses a basic recovery system in which the input of a compressor is coupled through an evaporator to the system to be evacuated and the output connected through a condenser to a refrigerant storage tank. The condenser and evaporator are combined in a single assembly through which air is circulated by a fan.
Manz et al., U.S. Pat. No. 4,805,416, discloses a complicated system in which various configurations recover refrigerant, purifies recovered refrigerant for removal of water and other contaminants, storage of used and/or purified refrigerant and recharging of a refrigeration system such as air conditioning and heat pump systems.
In Manz et al., supra, the input of a compressor is coupled through a filter unit and an evaporation section of a combined heat exchanger/oil separation unit to the refrigeration unit in which the refrigerant is to be recovered. The output of the compressor is coupled, through a condenser contained within the combined heat exchanger/oil separation unit, to a refrigerant storage tank. The refrigerant storage tank is situated on a scale having a pressure switch to indicate when the tank is filled by combining the total weight of the tank and refrigerant.
All filtering occurs in the filtering unit when the refrigerant is in a vapor form. A number of manual and electrically operated valve re-configure the device for various modes of operation. A vacuum pump is provided to evacuate the system during recharging.
These and other systems are presently known. Most systems having filtering capabilities contain independent filter units, as in Manz et al., and those having oil separators are based upon capturing the oil in the liquid phase within an oil separator by withdrawing vapor. In these systems some oil and contaminants are carried by the refrigerant in the vapor phase. The filter unit then further filters out the oil and contaminants.
The systems are often large and bulky and not suitable to transport to all job sites.
Other systems use a heat process to separate the oil from the refrigerant. These systems often operate at high temperature and can be dangerous.
Accordingly, it is the object of the present invention to provide a high efficiency refrigerant recovery and recycling system.
Another object of the present invention is to provide a refrigerant recovery and recycling system which is totally portable and can be easily transported to any job site.
A further object of the present invention is to provide a refrigerant recovery and recycling system which utilizes relatively low temperatures and a high efficiency filtering process to remove oil, moisture and sediment from the recovered refrigerant.
Still another object of the present invention is to provide a refrigerant recovery and recycling system which is easy to operate without complicated manipulation of controls either manually or electrically.
Still another object of the present invention is to provide a refrigerant recovery and recycling system which is highly reliable including only a few, easily serviced components.
Another object of the present invention is to provide a refrigerant recovery and recycling system which safely and reliably determines when a refrigerant storage tank is filled.